The present invention relates to personal telephone systems that are able to transmit and receive digital signals between fixed sets and fixed stations in a cordless system. More particularly, the present invention relates to answering machine call screening on such cordless telephone systems.
Cordless systems, such as time division multiple access (TDMA) cordless phone systems, provide a base unit which is able to provide connections for a plurality of mobile units, such as handsets. Such TDMA systems use time division to provide a plurality of slots, where the base (fixed part (FP)) transmits to an individual (portable part (PP)) mobile unit during a particular slot of time and receives from the individual mobile unit during a particular slot of time. Exemplary TDMA standards include WDCT, HOME-RF, and Bluetooth. One standard for TDMA systems is the Digital European Cordless Telecommunications DECT Common interface standard described in ETS 300 175-2 and ETS 300 175-3, published by the European Telecommunication Standards Institute. The DECT standard is also discussed in U.S. Pat. No. 6,078,574 entitled xe2x80x9cPROCESS AND APPARATUS FOR ACTION CONTROL IN A TIME SLOT METHODxe2x80x9d, to Boetzel et al. issued Jun. 20, 2000 and U.S. Pat. No. 6,088,338 entitled xe2x80x9cMETHOD AND SYSTEM FOR THE DETERMINATION OF THE PSCN PARAMETER STARTING FROM THE MFN PARAMETER IN A DECT CORDLESS TELEPHONE SYSTEMxe2x80x9d to Rossella et al. issued Jul. 11, 2000, which are incorporated by reference.
Non-cordless telephones that provide answering machine capability provide a feature known as call screening. Generally, this allows the user to listen to the party who is leaving a message on the answering machine before picking up, or instead of picking up. Typically, however, cordless telephones do not allow for answering machine call screening from the cordless units. As such, there is a need for a cordless system to provide for answering machine call screening.
To achieve the foregoing and other objects and in accordance with the purpose of the present invention, a system and method for answering machine call screening is provided.
According to one embodiment of the invention, when a call is received on an answering machine associated with a base part, the user at a portable part may select a call screen button. The resulting signal is received at the base part, which then enters a broadcast mode. The incoming answering machine message is broadcast to all handsets. In a TDMA system, an audio message is broadcast from a base part during a single time slot of a time division. The user at a particular portable part may then select a pick up button to pick up the call.
According to another embodiment of the invention, when the answering machine picks up, the user of a portable part can select the call screen button. The answering machine screening message is then transmitted to the user only, rather than broadcast to all the portable parts. The user at the portable part may then select a pick up button to pick up the call.
According to other embodiments of the present invention, the fixed part and the portable parts are individually and/or collectively configurable to automatically provide call screening. For example, at the fixed part, the user may use a set of key or menu commands that activate the call screening functionality. Similarly, at one or more of the portable parts, the user may configure the portable part for call screening. In certain embodiments, the configuration information may also be transmitted from the fixed part to the selected portable part and/or vice versa.
These and other features of the present invention will be described in more detail below in the detailed description of the invention and in conjunction with the following figures.